Human Population: Growth

1
Chapter 11 Human PopulationGrowth Carrying
Capacity
2
Factors Affecting Human Population Size
3
Current Status

• World Population Size 6.1 billion
• World Growth Rate 1.4, 84 million/year
• U.S. Population Size 273.6 million

6.1 billion people are breeding exponentially.
The process of fulfilling their needs and wants
is stripping Earth of its biotic capacity to
produce life.
4
Population Size (N)

• birth rate and death rate reported as the number
  per thousand people
• zero population growth (ZPG) occurs when births
  balance deaths

5
Why is population increasing?

• because of decreased death rate
• not because of increased birth rate.

6
Birth Death Rates
Birth and death rates are coming down, but death
rates have fallen more sharply than birth rates.
Hence more birth than death occur.

7
Population Growth
Worlds population will double in 52 years
8
Population projections by regions (1999 2025)
Over 95 of this increase will take place in
Developing Countries
9
Fertility Rates
1. Replacement-level fertility the number of
children a couple must bear to replace
themselves. Developed countries
2.1 Developing countries 2.5 (increased child
mortality) 2. Total fertility rate estimated
average number of children a woman will
have. Developed countries 1.3 Developing
countries 3.2
10
Fertility Rates
The tricky situation with the exponential
population growth If the global total fertility
rate of 2.9 will not change in 150 years there
would be 296 billion people on this
planet. (currently we have 6.1 billion)
11
Total fertility rates in 2000
12
Total fertility rates for the US
13
Factors Affecting Fertility Rates

• importance of child labor
• higher in Developing Countries
• cost of raising educating children
• lower in Developing Countries
• education employment opportunities for women
• higher in Developed Countries
• infant mortality
• lower in Developed Countries
• average age of marriage
• availability of reliable birth control
• availability of legal abortions
• religious beliefs, traditions, cultural norms
  that encourage large families.

14
Factors influencing the death rate thereby
leading to an increase in the worlds population

• Decline in death rate, especially in Developed
  Countries
• Higher live expectation
• - 75 yrs. in Developed Countries
• - 64 yrs. in Developing Countries but Africa
  50 yrs.
• - Improvements in medical and public health
  sciences, i.e. improved immunizations drugs.
• - Increase in high quality food supply
• green revolution (Video)
• -Improvements in sanitation and personal hygiene
• i.e. safer drinking water, better waste
  management.

15
Factors influencing the death rate thereby
leading to an increase in the worlds population
2. Lower infant mortality decrease in
undernutrition (insufficient food) decrease in
malnutrition (poor nutrition) -Improvements in
medical and public health sciences, i.e.
immunizations drugs. -Increase in high quality
food supply green revolution
(Video) -Improvements in sanitation and personal
hygiene i.e. safer drinking water etc..
16
Infant Mortality Rates
Between 1965 and 2000 the infant mortality rate
in Developed Countries dropped from 20 per 1,000
live birth to 8 and in Developing Countries
from 118 to 63.
17
Infant Mortality Rates
18
3. Human Carrying Capacity
Can the world/biosphere provide an adequate
standard for the increasing population or are we
at the limit?
19
Computer Models

• The Limits to Growth (1972) predicted economic
  environmental collapse

20
Slowing the Population Growth Case Studies
21
U.S. 278 million people

• fertility near replacement rate
• continued population increase because of
  immigration.

22
India 1 billion1/5 of worlds population

• 1952 first national family planning program
• program disappointing
• fertility still 3.5.

23
China 1.3 billion people 1/5 of worlds
population

• since 1970 efforts to better feed people
  control population growth
• strict population control measures prevent
  couples from having more than one child
• although considered coercive, the policy is
  significantly slowing population growth.

24
How to Reduce Population Growth?

• improve access to family planning reproductive
  health care
• improve heath care for infants, children,
  pregnant women
• improve equality between men women
• increase access to education, especially for
  girls
• increase the involvement of men in child rearing
  family planning
• reduce poverty
• reduce eliminate unsustainable patterns of
  production consumption.

25
Video Each group will present their findings next
week
Group I What methods and techniques were used
historically to feed an increasing world
population? Group II What problems occurred using
those methods and techniques? Group III What
alternatives are suggested to eliminate those
problems, but still feed the increasing world
population?